Experience of Equipment Preservation and Operation After Long Plant Outage at NFCL Kakinada

摘要

Idle equipment can suffer rapid and irreversible damage, when left unprotected and exposed to natural environment. In any chemical industry, expensive equipments like compressors, turbines, power generators, boilers, heat exchangers and pipelines, etc., begin to rust and corrode especially during long shutdowns due to exposure of moisture present in the atmospheric air. Moisture accelerates the rate of corrosion leading to deterioration, decrease in life of the equipments, equipment malfunction and even premature equipment failure. Apart from the bad corrosion, catalysts in ammonia plants will be in the reduced/active form, catalytic vessels can result in catastrophic failures, when the catalysts are exposed to atmospheric air or contaminants due to highly exothermic uncontrolled oxidation reactions. All equipments, when not in line, must be preserved in the As left' condition, when needed, they should be capable of going 'on line' immediately without any trouble. Otherwise, plants have to suffer with extended discontinuity in plant operation partly or full capacity due to equipment failures/problems, even sufficient raw materials or resources for full capacity are available. Due to non-availability of natural gas feed stock, NFCL total complex was taken shutdown on 3rd July 2014. Unit-1 & Unit-II plants were down by 41 days and 123 days, respectively, but plants were started without any major difficulty. This paper enumerates the best practices followed in entire NFCL complex for equipment preservation and difficulties faced till attaining the full capacity of plants due to continued short supply of natural gas for almost a year.